Toward Monitoring Surface and Subsurface Lakes on the Greenland Ice Sheet Using Sentinel-1 SAR and Landsat-8 OLI Imagery ...

• Main Authors: Miles, KE, Willis, IC, Benedek, CL, Williamson, AG, Tedesco, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers 2017
• Subjects: Greenland; hydrology; supraglacial lakes; drainage; satellite remote sensing; Sentinel-1; Landsat-8; Ice Sheet
• Online Access: https://dx.doi.org/10.17863/cam.11178; https://www.repository.cam.ac.uk/handle/1810/265785

Supraglacial lakes are an important component of the Greenland Ice Sheet's mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days vs. daily) but a higher spatial resolution (25–40 vs. 250–500 m), is then used together with a fully automated lake drainage detection algorithm. Rapid (<4 days) and slow (>4 days) drainages are investigated for both small (<0.125 km2, the minimum size detectable by MODIS) and large (≥0.125 km2) lakes through the summer. Drainage events of small lakes occur at lower elevations (mean 159 m), and slightly earlier (mean 4.5 days) in the melt season than those of large lakes. The analysis is ...